Tuesday, September 4, 2012

Does Natural Selection Create Diversity?

It's
very common for evolutionists to claim that natural selection creates
diversity. I could provide a hundred sources where they say this but
I chose one succinct one to include here:

After
spending time on the islands, he [Charles Darwin] soon developed a
theory that would contradict the creation of man and imply that all
species derived from common ancestors through a process called
natural selection. Natural selection is considered to be the biggest
factor resulting in the diversity of species and their genomes.
(source)

On
the one hand, I can understand the confusion: from a single
bear-kind, we have 8 modern species of bear. That's diversification,
right? But is natural selection the tool that creates diversity?
According to evolutionists, it is. I think they're more than a
little confused. There's no doubt that part of their problem is that
they notoriously conflate evolution and natural selection. It's
compounded by the fact that people who reject the Bible necessarily
hold irrational beliefs. It's typical for Bible critics to have
opinions in direct contradiction to reality.

Here's
the problem: natural selection removes unsuitable traits from a
population. That's all it ever does. So it's rather bizarre to
believe that removing traits can create diversity. To illustrate the
utter folly of such a notion, I will appeal once again to the most
famous of all examples of evolution – the peppered moth. If you
have a population of light and dark colored moths, and if birds
continuously ate the light colored moths, what would you have left?
That's right, you would eventually have a population of only dark
moths. You see, the population is less diverse than it
was; a population of light/dark moths becomes a population of dark
moths.

Here's
still one more, real world example. A while back, I blogged about a
Science
Daily article where scientists studied the effect on the
population of indigenous lizards when predatory lizards were released
onto a group of islands. The predatory lizards began eating the
smaller lizards and, in a few months, it was noticed that the
surviving lizards tended to have shorter legs. They speculated that
the short-legged lizards could climb better and so could escape the
predatory lizards. Here's a quote from the article:

Evolutionary
biology is by its nature an historical science, but the combination
of microevolutionary experimentation and macroevolutionary historical
analysis can provide a rich understanding about the genesis of
biological diversity.

Perhaps
the researcher cannot see the absurdity of this statement. The
population previously contained long and short-legged lizards. After
the experiment, the islands contained short-legged lizards. Once
again, the population is less diverse.

Natural
selection cannot explain the origin
of diversity. Instead, it only acts upon diversity already present
in the creature. It's easy to see, for example, how natural
selection can select short-legged lizards from a population which has
both long and short legs. However, natural selection doesn't explain
how the population came to have both long and short legs in the first
place!

Biblical
creation explains wonderfully what we observe. God created diversity
in the original kinds. Just like two mutt dogs can have pups of all
shapes, sizes, and colors, so too could the ancestral kinds on the
Ark have offspring that looked different from themselves. Natural
selection acted on this diversity and turned varied creatures into
specialized creatures, well adapted to their environment. God
created diversity; natural selection created species.

I
would dare say that evolutionists don't even understand their own
theory. The only candidate that could possibly add diversity to a
population is mutation. Theoretically, mutations can add feet to
fish. Mutations might make short legs become long legs. Mutations
(as the theory goes) could explain the origin of diversity. Once
mutations have introduced diversity, only then does natural selection
begin her methodical task of removing the unsuitable features.
Mutations are the hero of evolution. Natural selection is the
opposite of evolution.

But
as I've already said, evolutionists conflate natural selection and
evolution. The addition of novel traits to a population (i.e.
diversity) is evolution. The removal of unsuitable traits is natural
selection. If evolutionists want to demonstrate the origin of
diversity, they need to spend their time talking about trait-adding
mutations. However, trait-adding mutations are exceedingly rare - if they exist at all - so they really have no examples they can put
forth as evidence for their theory. Therefore, all they can do is
talk about is natural selection. They can say that natural selection
creates diversity. We know it can't. They can say that light/dark
moths becoming dark moths is evolution. We know it isn't. They can
say natural selection is evolution. Like I said, they
deny reality.

6 comments:

Some of your confusion might be alleviated by realizing that biologists use "variation" to speak of differences among individuals in the same species, whereas "diversity" means differences among species in a larger group (this may not apply to biologists who are not speaking on the subject of biology: a professor who complains about the lack of "diversity" in university hiring is probably not asking for more orangutans on the faculty).

Also, again, biologists use "evolution" to refer to the changes in the frequency of traits in a population. You can play Humpty-Dumpty and insist that words mean whatever you wish them to mean, but you cannot reasonably expect the rest of the English-speaking world to go along with you.

A single species can have great variety, but it cannot have diversity. Since natural selection will favor different traits in different ecological niches, it causes populations, as they split, to diverge in appearance and behavior and become more diverse.

Note that we naturally assume that natural selection applies to real populations, not merely abstractions: real populations experience a multitude of mutations in every generation, so there is always new variation from which to select.

Note also that, due to the interaction of many different genes to produce a given structure, variation can be near-continuous: that is, rather than simply "short legs" and "long legs," there can be legs of many different lengths, with the result of natural selection being not the extinction of this variation but its displacement, so that after selection, one still has legs of varying length, but the average length is different.

Another point: what do you mean when you say that "God created diversity among the original kinds," or, from a previous post, "The ancestral kinds on the Ark were necessarily genetically diverse." Do you mean that each "kind" originally comprised a large number of similar species, and that Noah took pairs from different species aboard the Ark?

Note that "two" is not a terribly high level of diversity. Or, if you mean "variety," it's perfectly possible to imagine a species with very high genetic variation, but the two individuals Noah took aboard the Ark could have had at most a total of four alleles per locus (one locus per chromosome, two chromosomes per individual). That would be high variation for a single mated pair, but vastly lower variation than would be normal for an entire breeding population.

You said, “Some of your confusion might be alleviated by realizing that biologists use "variation" to speak of differences among individuals in the same species, whereas "diversity" means differences among species in a larger group.”

That's interesting. I wasn't aware of that distinction. Even so, it doesn't diminish my point that natural selection cannot account for the “genesis of biodiversity” as claimed by Science Daily.

You said, “Also, again, biologists use "evolution" to refer to the changes in the frequency of traits in a population. You can play Humpty-Dumpty and insist that words mean whatever you wish them to mean, but you cannot reasonably expect the rest of the English-speaking world to go along with you.””

You know that I'm aware of that definition and that I've published it many times on my blog already. Evolutionists equivocate over the word. The fact that they all do it doesn't mean it's not equivocation (that's an argumentum ad populum). I don't mind if I'm in the minority. So was the little boy who said the emperor has no clothes.

You said, “A single species can have great variety, but it cannot have diversity. Since natural selection will favor different traits in different ecological niches, it causes populations, as they split, to diverge in appearance and behavior and become more diverse.”

Yes, I know. However, natural selection can only act upon traits already present in the population which means, as we go back in time, the ancestral populations necessarily had more variation. That's the opposite of evolution which predicts simple to complex.

You said, “Note that we naturally assume that natural selection applies to real populations, not merely abstractions: real populations experience a multitude of mutations in every generation, so there is always new variation from which to select.”

Did you really read my post? The ubiquitous claim of evolutionists is that natural selection creates diversity (and I mean diversity here and not variety). My point is that natural selection can only remove traits. Mutation is the only hope of new traits so it is mutation – and not natural selection – that creates diversity. By trying to sneak mutations into the conversation, you are perhaps tacitly conceding my point.

You said, “Note also that, due to the interaction of many different genes to produce a given structure, variation can be near-continuous: that is, rather than simply "short legs" and "long legs," there can be legs of many different lengths, with the result of natural selection being not the extinction of this variation but its displacement, so that after selection, one still has legs of varying length, but the average length is different.”

Naturally I assume they mean the average length. “Long” and “short” are subjective terms but they are the terms used in the article so I went with it. But we are still talking about less variety. Speciation is specialization and all creatures of the same species tend to look alike. In the case of humans, the global population will likely have a taller average height than the local population of Chinese. In other words, the Chinese, though they are diverse, are still less diverse than all human populations.

You said, “Another point: what do you mean when you say that "God created diversity among the original kinds," or, from a previous post, "The ancestral kinds on the Ark were necessarily genetically diverse." Do you mean that each "kind" originally comprised a large number of similar species, and that Noah took pairs from different species aboard the Ark?”

I mean both. I believe that God created diversity in the original kinds during the creation week. I also believe that the kinds (not species) represented on the Ark were “genetically diverse.” Two mutts, for example, could produce more variety among their pups than two “purebred” beagles could. You will notice the first quote I cited in my post said, “Natural selection is considered to be the biggest factor resulting in the diversity of species and their genomes.”

You said, “Note that "two" is not a terribly high level of diversity. Or, if you mean "variety," it's perfectly possible to imagine a species with very high genetic variation, but the two individuals Noah took aboard the Ark could have had at most a total of four alleles per locus (one locus per chromosome, two chromosomes per individual). That would be high variation for a single mated pair, but vastly lower variation than would be normal for an entire breeding population.”

In the case of humans, we know with certainty that we all have descended from two people, Adam and Eve. When we consider one particular trait, something like blood type, we know that there are more blood types than would ordinarily be possible given an original population of two. I'm not a doctor or anything but the only mechanism that I am aware that could have added “new” blood types is mutation. Of course, I again qualify my claim by saying that a mutation causing a “new” blood type in a creature that already has blood doesn't help in explaining how the creature came to have blood in the first place.

You state: "By trying to sneak mutations into the conversation, you are perhaps tacitly conceding my point." I might be inclined to agree with you, had you not a few lines earlier stated: "However, natural selection can only act upon traits already present in the population which means, as we go back in time, the ancestral populations necessarily had more variation."

No. That is a non sequitur of the first water. The fact that natural selection removes (some) variation does not say anything about contributors to new variation. Precisely because mutation occurs continuously in populations, as does natural selection, there is not only no necessity that ancestral populations had more variation, there is no obvious reason to suspect that they did. Mutations happen even when they are not mentioned explicitly in magazine articles.

Natural selection does not empty the pool of variation because the pool is constantly being refilled. And natural selection can conserve rare mutations that tend towards increased complexity even while weeding out the more common mutations that detrimentally simplify complex systems (of course, in some cases, there is no disadvantage -- there may even be advantage -- in such simplifications).

You tacitly admit some of this: the cat "kind" today must have more variation than the supposed pair of ancestral ur-felines aboard Noah's Ark, for all that natural selection must have been acting on felines throughout human history. So any claim that natural selection must tend to less variation -- much less decreased complexity -- is false even on your own terms.

To my point that ancestral populations were necessarily more diverse, you said, “That is a non sequitur of the first water. The fact that natural selection removes (some) variation does not say anything about contributors to new variation.”

You seem to forget the point of my post which is that NATURAL SELECTION cannot create diversity. The universal claim of evolutionists is that natural selection is the tool that explains the “genesis of biodiversity” (in the words of Science Daily). It's bologna. As I've said, the only hope for new variation is mutation – a point which you seem to agree with and have echoed again in this comment.

You said, “Precisely because mutation occurs continuously in populations, as does natural selection, there is not only no necessity that ancestral populations had more variation, there is no obvious reason to suspect that they did. Mutations happen even when they are not mentioned explicitly in magazine articles.”

I've talked about mutations many times in the past. Mutations happen regularly. However, “trait adding” mutations are either rare or nonexistent. The overwhelming majority of the examples of “evolution” cited by evolutionists involve the removal of traits from a population via natural selection. Do I really need to explain peppered moth “evolution” again?

If nearly all speciation is accomplished via natural selection (which it is), then the original “kind” necessarily had to have more genetic potential; in other words, the further back we go, the more genetically diverse the creature. That's the opposite of evolution's prediction of simple to complex.

You said, “Natural selection does not empty the pool of variation because the pool is constantly being refilled.”

Refilled? That's a pretty optimistic term, isn't it? Given the scarcity of (arguable) examples of trait-adding mutations, and given the ruthlessness of natural selection, then the pace traits are removed from a population far outstrips the introduction of “new” traits. Through mutations, polar bears have webbed toes. OK, I'll give you that one. Yet you would have me believe that mutations could add feathers to dinosaurs and turn them into birds! That would require a miles long parade of trait-adding, beneficial mutations. I don't usually appeal to incredulity but that defies reason.

You said, “You tacitly admit some of this: the cat "kind" today must have more variation than the supposed pair of ancestral ur-felines aboard Noah's Ark, for all that natural selection must have been acting on felines throughout human history. So any claim that natural selection musttend [sic] to less variation -- much less decreased complexity -- is false even on your own terms. “

Less variation in a species cannot be argued. There's a lot of variety among bears but less variety among polar bears. It is precisely because all members of a species are similar that we can identify them as a species. However, I don't recall ever suggesting species are less complex. Are you saying that since modern species lack they same potential for diverse offspring that was present in their ancestors, then they are “less complex”? I cannot see how that can be argued either. The original ursa-kind gave rise to eight modern species of bears. Polar bears have cubs that tend to look like polar bears.

RKBentley

About me

I'm a husband, a father, and a Christian. Being a Christian is not something I do on Sundays but rather it is who I am. My faith influences everything I do. Christians are commanded to always be ready to give an answer – a reason for the hope that is in us. I take that command seriously. Psalm 19:7 says that the testimony of the LORD is sure. If we base all of our thinking on the Bible, we can't go wrong. I started this blog to encourage other Christians and challenge critics on a variety of issues. Whether you agree or disagree with me, you're welcome here. Please follow me on Twitter and friend me on FaceBook! God bless!!